Classification

Beginnings of Classification Grouping of living things according to similar characteristics Early systems Walk, swim, fly Flesh, fur, scales Poisonous, nutritious, inedible

Classification Taxonomy taxo - arrangement or order -onomy - system of laws Aristotle classified organisms by the way they moved

Polynomial Nomenclature 1600’s – similar species put in common groups called genera (genus) Each species was given a long name Polynomial=genus name plus several descriptive words (Latin) Plant catnip = Nepeta floribus interrupte spicatus pedunculatis

Binomial Nomenclature 1700’s – Carolus Linnaeus Used genus and species name Called binomial nomenclature Bi = 2 nomia = name Wolf = Canis lupus Dog = Canis familiaris Human = Homo sapiens

Scientific Names Always in italics Genus and species names First letter of the genus name is capitalized All other letters are lower case Example: wolf: Canis lupus

Modern Classification Advances in microscopes and evolution have allowed for greater insight into classification Modern classification does two jobs: Groups organisms by basic characteristics Gives each organism a unique name

Modern Classification Advances in microscopes and evolution have allowed for greater insight into classification Modern classification does two jobs: Groups organisms by basic characteristics Gives each organism a unique name

Levels of Classification Domain Continent Kingdom Country Phylum State Class County Order City Family Street Genus House number Species Room

The Six Kingdoms

The Six Kingdoms

Create a flowchart that begins with the broadest level and becomes more specific.

Create a flowchart that begins with the broadest level and becomes more specific. Level 1 (most broad) This classification system has 5 levels. Each level is more specific than the last. Level 2 Level 3 Level 4 Level 5 (most specific)

Let’s classify the following animals:  

The Six Kingdoms *NOTE: Your worksheet lists two of the kingdoms as Archaebacteria and Eubacteria

How Are Evolutionary Relationships Determined Structural similarities: Closely related organisms have similar structures. Retracting claws = cat family. Sunflowers and dandelions = Asteraceae. Disk and ray flowers.

How Are Evolutionary Relationships Determined Breeding behavior: Mating behaviors can prevent different species from mating.

How Are Evolutionary Relationships Determined Geographic distribution: Finches on Galapagos share a common ancestor. Supported by probable isolation.

How Are Evolutionary Relationships Determined Chromosome comparisons: Closely related = similar number and structure of chromosomes. Cauliflower, cabbage, kale, and broccoli – chromosomes almost identical.

How Are Evolutionary Relationships Determined Biochemistry: Closely related = similar DNA sequences and proteins. DNA sequences suggest red pandas are related to raccoons and giant pandas to bears.

Phylogenetic Classification Phylogeny: evolutionary history of a species. Classification is based on phylogeny.

Cladistics Uses Phylogeny Organisms which evolve from a common ancestor share unique characteristics. Cladogram: branching diagram showing relationship through evolution.

Six-kingdom System Based on three criteria: The number of cells Presence or absence of nucleus Mode of nutrition

Prokaryotes: Two Kingdoms Archaebacteria and Eubacteria Prokaryotes Most are single celled Autotrophs or heterotrophs

Archaebacteria Few hundred species. Live in extreme environments. Swamps, deep-ocean hydrothermal vents, seawater evaporating ponds. Lipids, cell walls and DNA sequences are considerably different from other prokaryotes. Genes have more similar structure to eukaryotes.

Eubacteria All other bacteria: more than 10,000 species. Less complex genetics than archaebacteria or eukaryotes. Some cause diseases (strep throat and pneumonia) but most are harmless and many are helpful.

Bacteria

Kingdom Protista Eukaryotes Single celled Sexual reproduction by meiosis Autotrophs or heterotrophs

Protists - Eukaryotes

Kingdom Fungi Eukaryotes Single cell or multicellular Absorb nutrients from other organisms

Fungi

Kingdom Animalia Eukaryotes Multicellular Heterotrophs Most are mobile

Kingdom Plantae Eukaryotes Most are immobile Multicellular or single-celled Have cell walls Photosynthetic Autotrophs